[Comparison of gemstone spectral curve and CT value of gastric cancer with different pathological types and differentiation degrees]

Objective: To investigate the differences of gemstone spectral curve and CT value of gastric cancer with different pathological types and differentiation degrees. Methods: 91 cases of preoperative gemstone CT images with gastric cancer were collected, including 24 cases of mucinous carcinoma, 67 cases of non-mucinous carcinoma, 16 cases of signet ring cell carcinoma, 8 cases of mucinous adenocarcinoma, 32 cases of moderately differentiated adenocarcinoma and 35 cases of poorly differentiated adenocarcinoma. Gemstone CT spectral imaging was performed preoperatively, and the spectral curve of the lesion in venous phase was obtained by using GSI Viewer software, the slope of the curve was calculated, and 11 monoenergetic CT values of 40~140 keV (10 keV interval) were measured. The gemstone spectral curves and CT values of gastric cancer with different pathological types and differentiation degrees are compared. Results: The curve slopes of non-mucinous carcinoma, signet ring cell carcinoma and poorly differentiated adenocarcinoma were -1.92±0.53, -1.73±0.37 and -2.14±0.54, respectively. The absolute values were higher than those of mucinous carcinoma (-1.45±0.54), mucinous adenocarcinoma (-0.90±0.34) and moderately differentiated adenocarcinoma (-1.67±0.41), and the differences were all statistically significant (P<0.05). There were significant differences in monoenergetic CT values between mucinous and non-mucinous carcinomas at 40-140 keV (all P<0.05). The former was lower than the latter in different degrees, and the lower the energy, the greater the difference was. There were significant differences in monoenergetic CT values between signet ring cell carcinoma and mucinous adenocarcinoma at 40-100 keV (all P<0.05); monoenergetic CT values between poorly differentiated adenocarcinoma and moderately differentiated adenocarcinoma at 40-90 keV showed statistically significant differences (P<0.05). Conclusions: Gastric cancer with different pathological types and differentiation degrees have their characteristic spectral curves in venous phase, and the monoenergetic CT values are significantly different at low energy. The spectral curve of gemstone CT may be helpful to evaluate the pathological type and differentiation degree of gastric cancer before operation.